As long as it is properly preserved, overnight tea can be used. Many people are worried that nitrite will be produced, but it is not necessary. CCTV reporters have done experiments and sent a cup of tea brewed for 12 hours, a cup of tea brewed for 24 hours and a cup of tea just brewed to Beijing Institute of Nutrition Sources for testing. The results showed that the nitrite content of tea stored for 12 hours and 24 hours had no obvious change compared with that of freshly brewed tea, and the highest content was only about 1/4 of the national drinking water standard.
As for the breeding of bacteria, the content of sugar and amino acids in tea is very low, which is not a good "culture medium" for bacteria. If the lid is covered, it is difficult for bacteria in the air to fall into the teacup, so don't worry too much.
So how long can tea be stored without deterioration? How to better preserve tea?
How long it will go bad is inconclusive, which is closely related to the preservation environment, tea conditions, tea varieties and other factors, but if there is an odor or obvious changes in color and texture, it is better not to drink it.
It is suggested that the unfinished tea leaves be sealed with a lid or plastic wrap, and then stored in the refrigerator. Generally, it will not deteriorate in 8 ~ 12 hours. After all, one of the popular methods of making herbal tea now is to add cold water and tea leaves into a container, and then soak them in the refrigerator for 8 hours.